The present invention relates to a method for rapid clearance of landmines located freely on the surface of the ground or buried in the upper ground layer whereby major damage to the demining vehicle and the demining tool mounted thereon is avoided. The present invention also incorporates a dedicated design of the demining vehicle.
The expression xe2x80x98landminesxe2x80x99 used herein denotes both smaller types of anti-personnel (AP) mines as well as the significantly larger anti-vehicle and anti-tank mines.
As there is usually a mix of both types of mines in a mined zone one must be prepared to neutralise both types when demining mined zones.
To be able to neutralise buried mines of the above types the ground needs to be comprehensively worked down to a sufficient depth in the upper ground layer. Previously, most interest has been focused on military requirements for demining vehicles for rapid breaching of routes through minefields, while the final demining of minefields after the end of a conflict has been performed by the time consuming method of using probes or electromagnetic mine detectors. The latter are very reliable provided individual mines each contain at least some quantity of metal, but the number of false alarms owing to metal fragments in the ground can be considerable, especially in areas where battles have previously been fought. Electromagnetic mine detectors are, in fact, highly sensitive and require, moreover, trained personnel. This type of mine clearance is thus very time consuming and labour intensive. as is the use of probes, and is also very costly.
In latter years, however, various quarters have started to show an interest in developing mechanical mine clearance vehicles that operate in a similar way to mechanical rotary cultivators and which, in suitable ground, have displayed a capability for clearing considerably greater areas per unit of time than has been possible previously.
Demining devices operating like rotary cultivatorsxe2x80x94by means of toothed rollers, demining discs or some other type of toolxe2x80x94either xe2x80x98chewxe2x80x99 or tear apart any mines in their path or cause them to detonate either in or under the demining tool. The larger types of mines, however, often cause such extensive damage to the demining tool that it must be repaired or replaced before demining operations can continue. The mounting and/or driveline for the demining tool may also be damaged and may be much more difficult to rectify than the tool itself which can usually be replaced fairly easily, but each work stoppage should preferably be avoided, especially if they involve costs for irreparable materiel.
The desire to avoid as far as possible damage to the demining tool, its mount and drive function must, however, be combined with enablement of a sufficiently large mass and force on the demining tool that it constantly reaches the desired, pre-determined operating depth. This places majorxe2x80x94and partially contradictoryxe2x80x94demands on the design.
The present invention now offers a combined demining tool and drive-motor mount for demining vehicles of the type herein mentioned that enables a large mass to be exerted on the demining tool while also minimising damage to the demining tool in the event of any large mine detonations in or under the tool, and that also prevents damage to the tool""s drive function and engine.
As claimed in the present invention the demining vehicle""s demining tool that operates in the ground similar to a rotary cultivator or, to be more precise, the mounts which carry the rotating demining tool are interconnected with the engine that drives the tool, and in the present case also drives the demining vehicle, to form a longitudinal (in relation to the vehicle) interactive unit. This unit in turn is mounted on the chassis of the demining vehicle via a torsion shaft transverse to the longitudinal axis of the chassis which shaft is located at the same height as the engine and is so located longitudinally that a necessary part of its dead weight bears on the demining tool. The angle setting of the complete unit relative to the ground surface is in turn determined by dedicated devices that lift the ends of the demining tool that bear most of the dead weight of the unit. The tilt of the demining tool relative to the ground surface is what determines the operating depth of the tool in the ground. The mounting of the demining tool / engine unit around a torsional shaft transverse to the longitudinal axis of the chassis in combination with a lifting function journalled at the ends of the demining tool that bear most of the combined weight of the unit mean in turn that any mine detonation in or under the demining tool initiates an upwards swing of the demining tool / engine unit which will minimise the damage effect of the detonation on the demining tool itself, its mounts and drive function. The complete basic concept thus provides a method for reducing the effect of a mine detonation in or under the demining tool by means of a weighted-load counter-spring of the active system in which the enginexe2x80x94which must be present and must provide high outputxe2x80x94constitutes the main constituent of the counter-weight. As the demining tool and the engine constitute a coordinate unit in the longitudinal axis of the demining vehicle, the load on the drive coupling between the engine and demining tool is also reduced.
As claimed in a preferred variant of the demining vehicle in the present invention, the demining vehicle is equipped with further devices for as far as possible eliminating the negative effects of any mine detonations on the demining tool and its mounts and engine.
The demining tool mounts in the inverted cradle supporting the demining tool have thus been designed to be spring-loaded so that some of the stresses on the demining tool caused by any mine detonation can be assimilated immediately by the mounts.
Furthermore, the demining tool cradle is united with the engine of the above mentioned coordinate unit journalled around the transverse shaft by shock absorbers mounted between them with a great capability for assimilating stresses caused by any mine detonations.